I had the same problem with wger, tried it and it wouldn’t even let me select exercises from the list in the android app. I guess you could do it from the website but I just found it to be confusing.
The way that I worked around this issue was to add the workout plan via a web browser in a PC. It syncs with the app and after that it is working fine.
Now that my account passed the trial period I can even create workout exercises which I didn’t try yet so I can’t comment about it.
Otherwise this is the first decent workout open source app that I found that works for me.
I tried wger two times. To me, it was confusing and not easy to use.
I had the same problem with wger, tried it and it wouldn’t even let me select exercises from the list in the android app. I guess you could do it from the website but I just found it to be confusing.
The way that I worked around this issue was to add the workout plan via a web browser in a PC. It syncs with the app and after that it is working fine.
Now that my account passed the trial period I can even create workout exercises which I didn’t try yet so I can’t comment about it.
Otherwise this is the first decent workout open source app that I found that works for me.